研究者詳細 - 豊國　伸哉

論文 - 豊國　伸哉

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Stapled BIG3 helical peptide ERAP potentiates anti-tumour activity for breast cancer therapeutics. 国際誌

Yoshimaru T, Aihara K, Komatsu M, Matsushita Y, Okazaki Y, Toyokuni S, Honda J, Sasa M, Miyoshi Y, Otaka A, Katagiri T

Scientific reports 7 巻 ( 1 ) 頁： 1821 2017年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Scientific Reports

Estradiol (E2) and the oestrogen receptor-alpha (ERα) signalling pathway play pivotal roles in the proliferative activity of breast cancer cells. Recent findings show that the brefeldin A-inhibited guanine nucleotide-exchange protein 3-prohibitin 2 (BIG3-PHB2) complex plays a crucial role in E2/ERα signalling modulation in breast cancer cells. Moreover, specific inhibition of the BIG3-PHB2 interaction using the ERα activity-regulator synthetic peptide (ERAP: 165-177 amino acids), derived from α-helical BIG3 sequence, resulted in a significant anti-tumour effect. However, the duration of this effect was very short for viable clinical application. We developed the chemically modified ERAP using stapling methods (stapledERAP) to improve the duration of its antitumour effects. The stapledERAP specifically inhibited the BIG3-PHB2 interaction and exhibited long-lasting suppressive activity. Its intracellular localization without the membrane-permeable polyarginine sequence was possible via the formation of a stable α-helix structure by stapling. Tumour bearing-mice treated daily or weekly with stapledERAP effectively prevented the BIG3-PHB2 interaction, leading to complete regression of E2-dependent tumours in vivo. Most importantly, combination of stapledERAP with tamoxifen, fulvestrant, and everolimus caused synergistic inhibitory effects on growth of breast cancer cells. Our findings suggested that the stapled ERAP may be a promising anti-tumour drug to suppress luminal-type breast cancer growth.

DOI： 10.1038/s41598-017-01951-6

Significance of low mTORC1 activity in defining the characteristics of brain tumor stem cells. 査読有り

Han YP, Enomoto A, Shiraki Y, Wang SQ, Wang X, Toyokuni S, Asai N, Ushida K, Ara H, Ohka F, Wakabayashi T, Ma J, Natsume A, Takahashi M.

Nero Oncology 19 巻 ( 5 ) 頁： 636-647 2017年5月

Significance of low mTORC1 activity in defining the characteristics of brain tumor stem cells. 国際誌

Han YP, Enomoto A, Shiraki Y, Wang SQ, Wang X, Toyokuni S, Asai N, Ushida K, Ara H, Ohka F, Wakabayashi T, Ma J, Natsume A, Takahashi M

Neuro-oncology 19 巻 ( 5 ) 頁： 636 - 647 2017年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Neuro-Oncology

Background. The signifcance of mammalian target of rapamycin complex 1 (mTORC1) activity in the maintenance of cancer stem cells (CSCs) remains controversial. Previous fndings showed that mTORC1 activation depleted the population of leukemia stem cells in leukemia, while maintaining the stemness in pancreatic CSCs. The purpose of this study was to examine the currently unknown role and signifcance of mTORC1 activity in brain tumor stem cells (BTSCs). Methods. Basal mTORC1 activity and its kinetics were investigated in BTSC clones isolated from patients with glioblastoma and their differentiated progenies (DIFFs). The effects of nutrient deprivation and the mTORC1 inhibitors on cell proliferation were compared between the BTSCs and DIFFs. Tissue sections from patients with brain gliomas were examined for expression of BTSC markers and mTORC1 activity by immunohistochemistry. Results. BTSCs presented lower basal mTORC1 activity under each culture condition tested and a more rapid decline of mTORC1 activity after nutrient deprivation than observed in DIFFs. The self-renewal capacity of BTSCs was unaffected by mTORC1 inhibition, whereas it effectively suppressed DIFF proliferation. In agreement, immunohistochemical staining of glioma tissues revealed low mTORC1 activity in tumor cells positive for BTSC markers. In in vitro culture, BTSCs exhibited resistance to the antitumor agent temozolomide. Conclusions. Our fndings indicated the importance of low mTORC1 activity in maintaining the undifferentiated state of BTSCs, implicating the relevance of manipulating mTORC1 activity when developing future strategies that target BTSCs.

DOI： 10.1093/neuonc/now237

Primary extraskeletal osteosarcoma: a clinicopathological study of 18 cases focusing on MDM2 amplification status. 査読有り国際誌

Yamashita K, Kohashi K, Yamada Y, Nishida Y, Urakawa H, Oda Y, Toyokuni S

Human pathology 63 巻頁： 63 - 69 2017年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Human Pathology

Extraskeletal osteosarcoma (ESOS) is an uncommon malignant neoplasm. Most ESOSs are high grade, although some low-grade cases have been reported. A few cases of ESOS with MDM2 amplification have also been reported, suggesting some similarity to skeletal low-grade osteosarcoma such as parosteal osteosarcoma, where MDM2 is often amplified. However, the frequency of low-grade cases and cases with MDM2 amplification among ESOSs remains unknown, and their relationship is unclear. To clarify this, we examined 18 primary ESOS cases clinically, pathologically, and genetically, focusing on their MDM2 amplification status. Our cases comprised 10 men and 8 women whose mean age was 58.6 years; the most common site of the lesion was the thigh and buttock. There were one histologically low-grade case evaluated by biopsy specimen with an aggressive course and 2 relatively low-grade cases whose lesions were of low grade for the most part. MDM2 amplification status was revealed by fluorescence in situ hybridization in all 18 cases; 2 patients—histologically intermediate- and high-grade cases—were found to have MDM2 amplification. In conclusion, this study indicates that histologically low-grade and relatively low-grade cases of ESOS are not always associated with MDM2 amplification. The ESOS case with MDM2 amplification could be high grade, although MDM2-amplified dedifferentiated liposarcoma with osteogenic differentiation should be ruled out in making the diagnosis.

DOI： 10.1016/j.humpath.2017.02.007

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In response to Sharing different perspectives to understand asbestos-induced carcinogenesis: Acomment to Jiang et al. (2016) by Alessandro Francesco Gualtieri (2017) 国際誌 Open Access

Toyokuni Shinya, Jiang Li

CANCER SCIENCE 108 巻 ( 5 ) 頁： 1089 - 1090 2017年5月

Rheostatic CD44 isoform expression and its association with oxidative stress in human malignant mesothelioma. 国際誌

Chew SH, Okazaki Y, Akatsuka S, Wang S, Jiang L, Ohara Y, Ito F, Saya H, Sekido Y, Toyokuni S

Free radical biology & medicine 106 巻頁： 91 - 99 2017年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Free Radical Biology and Medicine

CD44 exists as a standard (CD44s) isoform and different variant isoforms (CD44v) due to alternative splicing. While the complex nature of these different isoforms has not been fully elucidated, CD44v expression has been shown to exert oncogenic effects by promoting tumor progression, metastasis and resistance of tumor cells to chemotherapy. One of the CD44v isoforms, CD44v8-10, was recently shown to protect cancer cells from oxidative stress by increasing the synthesis of glutathione (GSH). However, data regarding CD44 isoform expression in malignant mesothelioma (MM) are still lacking. Here, we show that most of the MM cell lines express both the CD44s and CD44v isoforms, in contrast to non-tumorigenic mesothelial cells, which express only CD44s. Moreover, we show here that these MM cell lines are positive for CD44 variable exon 9, with CD44v8-10 among the variant isoforms expressed. The expression of CD44 variable exon 9 was found to be statistically associated with NF2 inactivation, a common occurrence in MM. Knockdown of CD44 reduced the protein level of xCT, a cystine transporter, and increased oxidative stress. However, an increase in GSH was also observed and was associated with enhanced chemoresistance in CD44-knockdown cells. Increased GSH was mediated by the Nrf2/AP-1-induced upregulation of GCLC, a subunit of the enzyme catalyzing GSH synthesis. Our results thus suggest that the response to CD44 depletion is cell type-dependent and, in cases such as MM cells, compensatory pathway(s) might be activated rheostatically to account for the loss of CD44 and counteract enhanced oxidative stress.

DOI： 10.1016/j.freeradbiomed.2017.02.011

Protein kinase A inhibition facilitates the antitumor activity of xanthohumol, a valosin-containing protein inhibitor. 査読有り

Shikata Y, Yoshimaru T, Komatsu M, Katoh H, Sato R, Kanagaki S, Okazaki Y, Toyokuni S, Tashiro E, Ishikawa S, Katagiri T, Imoto M.

Cancer Science 108 巻 ( 4 ) 頁： 785-794 2017年4月

Iron and thiol redox signaling in cancer: An exquisite balance to escape ferroptosis. 査読有り Open Access

Toyokuni S, Ito F, Yamashita K, Okazaki Y, Akatsuka S.

Free Radical Biology & Medicine 108 巻頁： 610-626 2017年4月

Iron and thiol redox signaling in cancer: An exquisite balance to escape ferroptosis. 査読有り国際誌 Open Access

Toyokuni S, Ito F, Yamashita K, Okazaki Y, Akatsuka S

Free Radical Biology & Medicine 108 巻頁： 610-626 2017年4月

Protein kinase A inhibition facilitates the antitumor activity of xanthohumol, a valosin-containing protein inhibitor. 国際誌

Shikata Y, Yoshimaru T, Komatsu M, Katoh H, Sato R, Kanagaki S, Okazaki Y, Toyokuni S, Tashiro E, Ishikawa S, Katagiri T, Imoto M

Cancer science 108 巻 ( 4 ) 頁： 785 - 794 2017年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Cancer Science

Xanthohumol (XN), a simple prenylated chalcone, can be isolated from hops and has the potential to be a cancer chemopreventive agent against several human tumor cell lines. We previously identified valosin-containing protein (VCP) as a target of XN; VCP can also play crucial roles in cancer progression and prognosis. Therefore, we investigated the molecular mechanisms governing the contribution of VCP to the antitumor activity of XN. Several human tumor cell lines were treated with XN to investigate which human tumor cell lines are sensitive to XN. Several cell lines exhibited high sensitivity to XN both in vitro and in vivo. shRNA screening and bioinformatics analysis identified that the inhibition of the adenylate cyclase (AC) pathway synergistically facilitated apoptosis induced by VCP inhibition. These results suggest that there is crosstalk between the AC pathway and VCP function, and targeting both VCP and the AC pathway is a potential chemotherapeutic strategy for a subset of tumor cells.

DOI： 10.1111/cas.13175

Primary extraskeletal osteosarcoma: a clinicopathological study of 18 cases focusing on MDM2 amplification status. 査読有り

Yamashita K, Kohashi K, Yamada Y, Nishida Y, Urakawa H, Oda Y, Toyokuni S.

Human Pathology 63 巻頁： 63-69 2017年2月

Primary extraskeletal osteosarcoma: a clinicopathological study of 18 cases focusing on MDM2 amplification status. 査読有り国際誌

Yamashita K, Kohashi K, Yamada Y, Nishida Y, Urakawa H, Oda Y, Toyokuni S

Human Pathology 63 巻頁： 63-69 2017年2月

今月の特集2 微量金属元素と生体機能-メタロミクス研究から臨床検査へがんと微量金属元素

伊藤文哉, 豊國伸哉

臨床検査 61 巻 ( 2 ) 頁： 168 - 173 2017年2月

Rheostatic CD44 isoform expression and its association with oxidative stress in human malignant mesothelioma. 査読有り

Chew SH, Okazaki Y, Akatsuka S, Wang S, Jiang L, Ohara Y, Ito F, Saya H, Sekido Y, Toyokuni S.

Free Radical Biology & Medicine 106 巻頁： 91-99 2017年2月

Rheostatic CD44 isoform expression and its association with oxidative stress in human malignant mesothelioma. 査読有り国際誌

Chew SH, Okazaki Y, Akatsuka S, Wang S, Jiang L, Ohara Y, Ito F, Saya H, Sekido Y, Toyokuni S

Free Radical Biology & Medicine 106 巻頁： 91-99 2017年2月

Clinicopathological and Molecular Features of Dedifferentiated Liposarcoma with Ossification: A Comparative Study with Dedifferentiated Liposarcoma without Ossification and Extraskeletal Osteosarcoma

Yamashita Kyoko, Kohashi Kenichi, Yamada Yuichi, Oda Yoshinao, Toyokuni Shinya

MODERN PATHOLOGY 30 巻頁： 27A-27A 2017年2月

Clinicopathological and Molecular Features of Dedifferentiated Liposarcoma with Ossification: A Comparative Study with Dedifferentiated Liposarcoma without Ossification and Extraskeletal Osteosarcoma

Yamashita Kyoko, Kohashi Kenichi, Yamada Yuichi, Oda Yoshinao, Toyokuni Shinya

LABORATORY INVESTIGATION 97 巻頁： 27A - 27A 2017年2月

Clinicopathological and Molecular Features of Dedifferentiated Liposarcoma with Ossification: A Comparative Study with Dedifferentiated Liposarcoma without Ossification and Extraskeletal Osteosarcoma 国際誌

Kyoko Yamashita, Kenichi Kohashi, Yuichi Yamada, Yoshinao Oda, Shinya Toyokuni

LABORATORY INVESTIGATION 97 巻頁： 27A - 27A 2017年2月

Kyoko Yamashita, Kenichi Kohashi, Yuichi Yamada, Yoshinao Oda, Shinya Toyokuni

MODERN PATHOLOGY 30 巻頁： 27A - 27A 2017年2月

Future perspective of strategic non-thermal plasma therapy for cancer treatment.

Kajiyama H, Utsumi F, Nakamura K, Tanaka H, Toyokuni S, Hori M, Kikkawa F

Journal of clinical biochemistry and nutrition 60 巻 ( 1 ) 頁： 33 - 38 2017年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人　日本酸化ストレス学会

The therapeutic effects of non-thermal plasma are expected in the medical fields, including hemostasis, vascularization, prevention of organ adhesion, and cell proliferation. Cancer is an internal enemy arising from normal tissue in the body. The prognosis of metastatic and recurrent cancers is still poor despite advances in medicine. To apply non-thermal plasma in cancer treatment is now on going. The mechanism of the proliferation-inhibitory effect of plasma is reactive nitrogen oxide species/reactive oxygen species production in cells. There are a number of problems to be overcome, such as existence of intrinsic reactive oxygen species/ reactive nitrogen species scavengers and the shallow infiltration of plasma on tumor surface. The current reviews makes referral to the study results of plasma therapy clarified so far, the possibility of its application in the future.

DOI： 10.3164/jcbn.16-65

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論文 - 豊國 伸哉

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論文 - 豊國　伸哉